| 摘要 |
<p>A function generator has two sets of biased rectifying circuits connected in parallel between an input and an output. For a steadily increasing input voltage, a first group of similarly poled rectifying circuits switch off in sequence. Subsequently, for a continuing increase in the input voltage, a second group of rectifying circuits poled oppositely to the first group switch on in sequence. Their outputs are summed, via an inverting circuit, to generate a function generator output characteristic (output voltage verses input voltage) of six segments, concave upwards. In addition, there is a non-rectifying circuit connection via a resistor from input to output of the function generator giving a straight-line characteristic which is added to the characteristic of the rectifying circuits to give a resultant characteristic which can provide a uniformly increasing slope with an increasing input signal. The central part of the output characteristic is arranged, by the addition of the straight-line characteristic, to pass to one side of the origin across the input equals zero line. Since the errors in any segment of a characteristic depend on how many of the rectifying circuits are switched on, the errors are therefor cumulative from the center of the output characteristic outwards in both directions, instead of from one end to the other, and the maximum errors are thus reduced.</p> |
